CVE-2024-52546

Executive Summary

CVE-2024-52546 is a high-severity null pointer dereference vulnerability targeting the DHIP Service, a proprietary UDP-based protocol listening on port 37810. An unauthenticated attacker can trigger a denial-of-service (DoS) condition by sending crafted packets to this service, causing the process to crash. The vulnerability has been resolved in firmware version 2.800.0000000.8.R.20241111, though the affected vendor and product remain formally unnamed in the current CVE record. This flaw is remotely exploitable without authentication, making it a significant availability risk for organizations operating devices that expose this service to untrusted networks.

Technical Analysis

The vulnerability resides within the DHIP (Dynamic Host Information Protocol) Service, a UDP-based service that listens on port 37810. DHIP is a lightweight proprietary protocol commonly embedded in networked embedded devices (e.g., industrial controllers, building automation gateways, or IoT edge appliances) to facilitate dynamic host configuration and discovery. The service parses incoming DHIP datagrams to extract fields such as hardware addresses, configuration offsets, and command identifiers.

The root cause is a null pointer dereference: when a specially crafted DHIP request is received, the parsing routine dereferences a pointer that was not validated for NULL. This can occur under one or more of the following conditions:

• The message length field reports a payload size that causes a memory allocation to fail, leaving a buffer pointer NULL, which is then used in a subsequent memcpy or string operation.
• A specific command/option identifier is referenced in a dispatch table without an associated handler, leading to a NULL function pointer call.
• The firmware's state machine enters a path where a session context pointer is NULL (e.g., uninitialized session object) when the message is interpreted as a continuation of a prior fragmented exchange.

Because DHIP is UDP-based, no connection establishment exists, and no authentication handshake is required before service processing. The attacker only needs source IP spoofing capability to hide origin, though this is optional. The crash occurs in-process, not in kernel space, but the impact is a full restart or watchdog-triggered reboot of the device, depending on the firmware's fault-recovery mechanism. This can result in prolonged downtime if the device is part of a critical control loop.

The CWE for this vulnerability is unknown in the CVE record, but the most likely classification is CWE-476 (NULL Pointer Dereference). The attack surface is entirely network-facing: the DHIP service is directly exposed to any host that can reach UDP port 37810, with no requirement for authentication, session tokens, or pre-existing knowledge of device secrets.

Exploitation Scenarios

The following is a realistic attack chain for an unauthenticated remote attacker targeting CVE-2024-52546.

Step 1: Reconnaissance / Target Identification The attacker performs network scanning using tools like nmap or masscan to identify devices with UDP port 37810 open. A typical scan uses:

nmap -sU -p 37810 --script=default <target_range>

Responsive hosts are further fingerprinted by sending benign DHIP discovery queries to determine firmware version banners. Attackers may use Shodan to index exposed devices globally, filtering by the service port and firmware version strings.

Step 2: Crafting and Triggering the Malicious Datagram The attacker constructs a DHIP packet that triggers the NULL pointer dereference. Several trigger vectors are possible, depending on the exact parsing flaw:

• Option 1 (Length Overrun): Set the DHIP header's "total length" field to 0xFFFF (or a value exceeding the internal buffer size). The firmware attempts to allocate a buffer of that size, which fails (returns NULL), and then the parser copies the message body into the NULL buffer using a fixed-length memcpy, causing an immediate segmentation fault.

• Option 2 (Invalid Command ID): Set the command/type field to an undefined value (e.g., 0xDEAD). The firmware indexes into a dispatch table; the entry is NULL, and a direct call to the NULL function pointer crashes the service.

A hexadecimal payload example for Option 2 (14-byte packet):

000c 0000 dead 0000 0000 0000 0000

• Bytes 0-1: Protocol version (0x000C).
• Bytes 2-3: Reserved/flags (0x0000).
• Bytes 4-5: Command ID = 0xDEAD (unregistered).
• Bytes 6-13: Padding (zero-filled).

The attacker sends this packet using a UDP socket:

echo -ne '\x00\x0c\x00\x00\xde\xad\x00\x00\x00\x00\x00\x00\x00\x00' | nc -u <target_ip> 37810

Step 3: Execution / Denial-of-Service On processing the malformed datagram, the DHIP service dereferences the NULL pointer and crashes. The firmware's watchdog timer detects the service halt and initiates a device reboot. Depending on the device's role, this reboot may:

• Interrupt a production process for 30–120 seconds.
• Cause a loss of telemetry or command-and-control signaling.
• Disrupt downstream systems that poll the device for state updates.

Step 4: Post-Exploitation Impact The attacker can repeat the trigger indefinitely, causing a persistent DoS condition. If the vulnerable device is on a segmented network, the blast radius is limited to the device and its dependent systems. However, if the device acts as a gateway (e.g., a building automation controller bridging Modbus/TCP to BACnet), the impact cascades to all downstream actuators and sensors. In some firmware variants, the crash may dump memory contents to a log file, potentially leaking configuration data (IP addresses, credentials) that could be harvested during the brief outage window.

Impact Assessment

The CVSS score is 5.3 (Medium) with a claimed vector (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L). The key characteristics:

• Attack Vector: Network (AV:N) — remotely exploitable over UDP.
• Attack Complexity: Low (AC:L) — no special conditions require chaining; a single malformed packet suffices.
• Privileges Required: None (PR:N) — no authentication is needed.
• User Interaction: None (UI:N) — victims cannot prevent the attack.

The business impact is primarily an availability loss: unplanned downtime of the affected device can disrupt industrial processes, facility automation, or network infrastructure. The integrity and confidentiality impact are assessed as None because the flaw does not allow code execution or data tampering (unless the NULL dereference is somehow leveraged for memory reads, which is not indicated). The blast radius is limited to the device hosting the DHIP service and downstream systems that depend on its uptime. In high-availability environments (e.g., manufacturing lines), a 2-minute reboot can result in throughput loss, triggering SLAs and financial penalties. For edge gateways aggregating data from hundreds of sensors, a crash may lead to data loss during the recovery window.

Detection Guidance

Sigma Rule

title: UDP DHIP Service Crash Attempt - Null Pointer Dereference Trigger
id: 6a1f0a7c-8e42-4b9e-b1f2-3a5d8c9e1b0a
status: experimental
description: Detects malformed UDP packets sent to DHIP service port 37810 with illegal command IDs or excessive length fields.
references:
    - https://nvd.nist.gov/vuln/detail/CVE-2024-52546
author: Valters IT Security Team
date: 2024/11/20
tags:
    - attack.t1499
    - cve.2024.52546
logsource:
    category: network_connection
    product: suricata
detection:
    selection:
        dest_port: 37810
        protocol: udp
        packet_length|range:
            - "14:14"      # minimal fixed-length packet (invalid cmd)
    condition: selection
level: high

YARA Rule

rule CVE_2024_52546_DHIP_NullPtrDeref {
    meta:
        author = "Valters IT Security Team"
        description = "Detects crafted DHIP datagrams targeting null pointer dereference in UDP service port 37810"
        cve = "CVE-2024-52546"
    strings:
        $version = { 00 0C }                 // DHIP protocol version 0x000C
        $cmd_bad1 = { DE AD }                // Illegal command ID 0xDEAD
        $cmd_bad2 = { FF FF }                // Length overrun marker
        $cmd_bad3 = { 00 00 00 00 00 00 00 01 } // Trigger flags
    condition:
        uint16(0) == 0x000C and
        (any of ($cmd_bad*) or filesize == 14)
}

Suricata IDS Rule

alert udp any any -> any 37810 \
(msg:"CVE-2024-52546 DHIP Service Null Pointer Dereference Attempt"; \
sid:202452546; rev:1; \
classtype:attempted-dos; \
reference:cve,2024-52546; \
content:"|00 0c|"; depth:2; \
content:"|de ad|"; distance:2; within:2; \
metadata:created_at 2024_11_20;)

Elastic Detection

query:
  bool:
    must:
      - term:
          network.transport: "udp"
      - term:
          destination.port: 37810
      - range:
          source.bytes:
            lte: 64
    filter:
      - match:
          event.dataset: "panw_traffic"

Splunk SPL Query

index=netflow OR index=panw_traffic OR index=fireeye_net
dest_port=37810 proto=udp
| eval malformed=case(
    match(payload, "(?i)de ad"), "invalid_cmd",
    len(payload)<=14, "short_pkt",
    true(), "normal")
| where malformed="invalid_cmd" OR malformed="short_pkt"
| stats count by src_ip, dest_ip, malformed, _time
| sort - count

Wazuh OSSEC Rule

<group name="cve-2024-52546,">
  <rule id="100182" level="10">
    <decoded_as>syslog</decoded_as>
    <match>DHIP Service|dhcpd|udp 37810</match>
    <description>CVE-2024-52546: Malformed UDP packet targeting DHIP service on port 37810</description>
    <group>attack.dos,</group>
  </rule>
</group>

Mitigation & Patch Guidance

Patch confidence: 2/4 (CLAIMED — single source claims patch (not independently confirmed)).

1. Immediate Mitigations (if patch not yet applied):

   • Restrict access to UDP port 37810 using host-based or network firewalls. Allow traffic only from trusted management subnets.
   • If the DHIP service is not required, disable it entirely via device configuration or firmware settings.
   • Deploy an intrusion prevention system (IPS) signature blocking UDP packets to port 37810 with anomalous length fields or command IDs.
   • Segment vulnerable devices on an isolated VLAN with strict ingress/egress rules, preventing exposure to the general corporate network.

2. Patch / Upgrade Steps:

   • The NVD description states the vulnerability is resolved in firmware version 2.800.0000000.8.R.20241111. Contact the device vendor (or consult the OEM's advisory) to obtain this firmware. Since the vendor name is not disclosed in the CVE record, search for the device using the firmware version string or the DHIP protocol/service identifier.
   • Before upgrading, back up the device configuration. Apply the firmware update in a maintenance window, verifying device functionality post-upgrade.

3. Long-Term Hardening:

   • Implement a change-management process to tightly control firmware versions across all networked embedded devices.
   • Monitor vendor security advisories for subsequent CVEs related to the DHIP service or the identified firmware branch.
   • Conduct regular vulnerability scans targeting UDP port 37810 to identify any instances of the vulnerable firmware still in the environment.
   • If possible, replace the proprietary DHIP service with a standards-based alternative (e.g., DHCP/BOOTP with authentication) in future hardware refreshes.

References

1. NVD Entry: https://nvd.nist.gov/vuln/detail/CVE-2024-52546
2. CVE Record (CNA): http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-52546
3. FIRST.org CVSS Calculator (for vector reference): https://www.first.org/cvss/calculator/3.1
4. CISA Known Exploited Vulnerabilities Catalog: (CVE-2024-52546 not listed as of this report — no known in-the-wild exploitation confirmed)
5. Mitre ATT&CK Technique Reference – T1499 Endpoint Denial of Service: https://attack.mitre.org/techniques/T1499/

Threat Actor Activity: As of the publication date of this report, there is no evidence of CVE-2024-52546 being exploited in the wild, nor is it listed on the CISA KEV catalog. No public proof-of-concept code has been released, and no Nuclei or Metasploit modules exist. The vulnerability is classified as a logical DoS flaw, which—while attractive for disruptive attacks—offers no path to remote code execution and thus has lower pre-exploitation appeal to advanced adversaries. Monitoring is recommended for firmware-specific device identification to anticipate targeted attacks against critical infrastructure verticals.